Apparatus for swaging gold crowns.



No. 674,232. Patented May I4, |901.

B B. BREWER W. M. H. BURFEIND.

lAPPARATUS FR SWAGING GOLD CBUWNS.

l l- (Apphcmon me .rune 11, 1900.) (No Model.) t

Hununmu UNITED STATES PATENT@ BENJAMIN B. BREWER AND WILLIAM M. H. BURFEIND, OF SAN FRANCISCO, CALIFORNIA.

APPARATUS FOR SWAGING GOLD CROWNS.

SPECIFICATIONforming part of Letters Patent No. 674,232, dated May 14, 1901. Application iiled June 1l, 1900. Serial No. 19,944. (No model.)

.To all whom zit may concern:

Beit known that we, BENJAMIN B. BREWER and WILLIAM M.l H. BUREEIND, citizens of the United States, residing at San Francisco,

in the county of San Francisco and State of California,l1ave invented certain new and useful Improvements in Apparatus for Swaging Gold Crowns, of which the following is aspecification. v

Io Our invention relates to an improved swaging apparatus for making seamless contour gold crowns for teeth; and the object of our invention is to make a perfectly-fitting crownof any desired shape, contour, and occlusion x 5 without the use of solder.

Our invention therefore resides in the novel construction, combination, and arrangement of parts for the above ends, hereinafter fully specified and particularly pointed out in the 2o claims.

In the accompanying drawings, Figure 1 is a perspective view of the lower section of the casing. Fig. 2 is a similar View of the upper section. Fig. 3 is a similar view of a core used in forming a thimble. Fig. 4 is a sectional view of the core and one of the casingsections used as a mold to form the thimble. Fig. 5 is a sectional view of the parts arranged in position to form a lead casting around the gold cup Ior crown, and Fig. 6 is a sectional view of the parts arranged for swaging the gold cup into the required shape.

The nature of our invention will be understood more readily by following in detail the manner in which we apply the same and by describing the diiferent parts of the apparatus in the order in which they are used in the operation of swaging gold crowns by means thereof.

Referring therefore to Fig. 2, it will be seen that ot represents the upper cylindrical section of a casing, having dowel-pins b to fit into recesses c in the lower cylindrical casingsection d. e is a core frusto-conical in form. Using the part e as a core in the center of the section a, used as a mold, as shown in Fig. 4,

a leaden thirnble f is cast. This thimble f is now placedin the bottom of the section d, in which it fits snugly, since it was cast in the 5o section ct, which is the same diameter as d. The gold cup g which is to be swaged is now placed upon the top of the lead thimble f, centrally of the section el, as shown in Fig. 5. Molten lead or other soft metal is now poured around the gold cup up to the up per edge of said cup, as shown at h, care being taken to prevent the molten lead running over the upper edge of the cup, which may be done by inserting therein a stick of wood Z, which about fills the cup. The stick is now withdrawn and thereisinserted in the cup in its place the form i, previouslyprepared, to which the crown is to be swaged, and the form is now cut oif even with the top of the cup. The section a is now fitted upon the top of the section d by means oi" the dowelpins b and recesses c to serve as a guide for the punch j, through which power is to be applied for swaging the cup. A disk of lead lo, fitting within the cylindrical section a,is placed upon 7o the top of the cast lead h and the cup g, and the end of the punch j is inserted in said secytion a above the disk of the lead Zt.

The whole of the above apparatus so arranged is now placed upon a suitable anvil, and the punch is driven down by a heavy hammer until the lead has been compressed or swaged in the cylindrical casing to such an extent that the opening or recess n in the leaden thimble f has been completely closed. 8o Then by driving the entire mass out of the casing the lead disk 7c and the thimble f will separate and fall off from the portion h, the gold crown remaining in the latter. By means of suitably-constructed cutting-nippers the portion h is split free from the gold crown, which will be found to be accurately outlined and compressed or swaged to the interior form as desired.

We claim- 9o 1. In an apparatus for swaging dental crowns, the combination of a casing having a substantially cylindrical chamber, a form within the chamber to which the crown is to be swaged,a soft-metal jacket around the crown, and a hollow soft-metal support or -thimble below the crown arranged to receive the impact of the hammer transmitted through the jacket and to have its cavity substantially closed thereby in the swaging of the crown by said impact, substantially as described.

2. In an apparatus for swaging dental IOO crowns, the combination of a casing, a yielding support for the crown within the easing, a form within the crown, to which it is to be swafred, and an internal jacket of soft metal cast around the crown, substantially as described.

3. In an apparatus for swaging dental crowns, the combination of a casing having a substantially cylindrical chamber, a form within the chamber to which the crown is to be swaged, a jacket of soft metal cast around the crown, and a hollow soft-metal su pportbelow the crown7 substantialb1 as described.

4. In an apparatus for swaging dental crowns, the combination of a casing having a cylindrical chamber open at both ends, a cy' lindrical plunger fitting snugly in said charnber, a soft-metal support in said chamber near one end for the crown, a form in the-chamber to which the crown is to be swaged and a softmetal jacket in the chamber around the crown, substantially as described.

In witness whereof we have hereunto set our hands in the presence of two subscribing witnesses.

BENJAMIN B. BREWER. WILLIAM M. H. BURFEIND.

Witnesses: i

FRANCIS M. WRIGHT, FLORENCE H. WIGAND. 

